Page 464 - My FlipBook

4G0

SECTION IV.

OP THE MANNER OF TAKING THE SHAPE AND FIGURE OF
THE MOUTH.

It is necessary in order to know exactly the shape and
size of the mouth, so as to enable us to form artificial teeth
perfectly adapted to the gum and mouth, for us to take a
cast of the teeth, and gums,-&c. This we do by taking a
piece of wax (bees-wax is usually employed) and softci i lg
it in warm water or by a fire, and then pressing it upon
the gum and teeth, which will give the exact impression of
the cavity, gum, remaining teeth, &c. We then, after suffer-
ing the wax to harden, pour upon it a paste of the sulphate
of lime, gypsum, plaister of paris, and suffer this to harden ;
then melt the wax from the plaister, and we have an exact
model of the mouth, if every part of our manipulations have
been correctly done. It requires practice to perform this
part of our art well. When we wish to insert whole jaws
of teeth, it is necessary to take a cast of both jaws. After
having obtained our model, we shall be enabled to form our
artificial teeth by it, so that they will be easily adapted to the
mouth of the patient. Much depends upon the nicety and
exact correctness of our model, and great care is required in
taking it. The plaister should be calcined before using it,
and sifted so as to be c ean, free from sticks, &c.
For whole sets, brass castings are taken from the models,
so as to shape the gold plate on the brass models.